Over the Eastern Plains of Colorado, there are very few features to navigate by, and my instructor had forbidden use of GPS for this trip. We were navigating by VOR from Fort Collins-Loveland (KFNL) to Sterling (KSTK) 80 NM away. It took about 20 minutes of flying by pilotage alone before we picked up the Sterling VOR on NAV1, dialed in the OBS and began happily keeping the needle centered. Shortly, however, I became aware that the one feature between KFNL and KSTK, a reservoir, wasn’t where it was supposed to be. We were flying straight toward it, whereas the line on my sectional was well north of it. Fortunately, this sircraft was equipped with a second NAV radio, so we tuned it to STK, centered its needle, and promptly began turning left to keep it centered. I then found a tower on the sectional that should pass less than a quarter-mile to our right if I were back on the right course. Less than a minute later, we spotted the tower right where I had predicted it would be.

Based on the differences we were seeing, we concluded that NAV1 was off by about 6 degrees. Now, whenever I go cross-country, I make sure to familiarize myself with features I’m likely to see along the route and have the VOR tuned and verified to back up the GPS. Haven’t gotten lost yet!